This biome contains a nutrient-rich environment created by falling leaves and trapped organic materials from the large trees, and it provides the ecosystem service of filtering pollutants from water.
coral reefs
freshwater wetlands
open ocean
rivers

The correct answer is B. FRESHWATER WETLANDS. Freshwater wetlands is the biome which contains a nutrient-rich environment created by falling leaves and trapped organic materials from the large trees, and it provides the ecosystem service of filtering pollutants from water.

Explanation:

Wet-lands are areas that are flooded with water and contain unique kinds of plants that cannot be found elsewhere. The plants and trees in the wetlands are adapted to store excess nutrients and minerals in them, hence when their  leaves fall off they contain a high content of minerals and nutrients. The plants in the wetlands are also adapted to trap sediments and metals in them serving as a filter to the water.